SQL Server 2017

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CREATE TABLE dbo.findUnique
(
	Col01	VARCHAR(50),
	Col02	INT,
	Col03	VARCHAR(50),
	Col04	INT
)
INSERT INTO dbo.findUnique
VALUES
( 'Red',   1, 'Box', 1 ),
( 'Red',   2, 'Box', 1 ),
( 'Red',   1, 'Box', 2 ),
( 'Green', 2, 'Box', 2 ),
( 'Green', 1, 'Box', 3 ),
( 'Green', 2, 'Marble', 3 ),
( 'Yellow', 1, 'Marble', 4 ),
( 'Yellow', 2, 'Marble', 4 ),
( 'Yellow', 1, 'Marble', 5 )
9 rows affected

CREATE STATISTICS findUnique_1_2_3_4 ON dbo.findUnique (Col01, Col02, Col03, Col04)
CREATE STATISTICS findUnique_1_2_3 ON dbo.findUnique (Col01, Col02, Col03)
CREATE STATISTICS findUnique_1_2_4 ON dbo.findUnique (Col01, Col02, Col04)
CREATE STATISTICS findUnique_1_3_4 ON dbo.findUnique (Col01, Col03, Col04)
CREATE STATISTICS findUnique_2_3_4 ON dbo.findUnique (Col02, Col03, Col04)
CREATE STATISTICS findUnique_1_2 ON dbo.findUnique (Col01, Col02)
CREATE STATISTICS findUnique_1_3 ON dbo.findUnique (Col01, Col03)
CREATE STATISTICS findUnique_1_4 ON dbo.findUnique (Col01, Col04)
CREATE STATISTICS findUnique_2_3 ON dbo.findUnique (Col02, Col03)
CREATE STATISTICS findUnique_2_4 ON dbo.findUnique (Col02, Col04)
CREATE STATISTICS findUnique_3_4 ON dbo.findUnique (Col03, Col04)
CREATE STATISTICS findUnique_1 ON dbo.findUnique (Col01)
CREATE STATISTICS findUnique_2 ON dbo.findUnique (Col02)
CREATE STATISTICS findUnique_3 ON dbo.findUnique (Col03)
CREATE STATISTICS findUnique_4 ON dbo.findUnique (Col04)
SET NOCOUNT ON

DECLARE	@tableName NVARCHAR(256) = 'dbo.findUnique'
	  , @statsName NVARCHAR(128), @dSQL NVARCHAR(1024)

DECLARE @stats_densityVector TABLE
(
	StatName	NVARCHAR(1024),
	AllDensity	REAL,
	AvgLength	BIGINT,
	Columns		NVARCHAR(1024)
)

DECLARE statsHeader CURSOR
FOR
	SELECT	name AS stats_name
	FROM	sys.stats s
	WHERE	s.object_id = OBJECT_ID(@tableName)

OPEN statsHeader
FETCH NEXT FROM statsHeader
INTO	@statsName

WHILE @@FETCH_STATUS = 0
BEGIN
	
	SET @dSQL = 'DBCC SHOW_STATISTICS (''' + @tableName + ''', ' + @statsName + ') WITH DENSITY_VECTOR, NO_INFOMSGS'
	INSERT INTO @stats_densityVector (AllDensity, AvgLength, Columns)
	EXEC (@dSQL)

	UPDATE @stats_densityVector
	SET StatName = @statsName
	WHERE StatName IS NULL

	FETCH NEXT FROM statsHeader
	INTO	@statsName
END

CLOSE statsHeader
DEALLOCATE statsHeader

SET NOCOUNT OFF

SELECT	OBJECT_SCHEMA_NAME(s.object_id) + '.' + OBJECT_NAME(s.object_id) AS table_name
		, dv.*
		, sp.rows_sampled
		, sp.rows
		, (1.0 * sp.rows_sampled) / (1.0 * sp.rows) AS sample_pct
FROM sys.stats s 
		CROSS APPLY sys.dm_db_stats_properties (s.object_id, s.stats_id) sp
		INNER JOIN @stats_densityVector dv
			ON dv.StatName = s.name
WHERE s.object_id = OBJECT_ID(@tableName)
ORDER BY dv.AllDensity, dv.AvgLength


table_name
StatName
AllDensity
AvgLength
Columns
rows_sampled
rows
sample_pct


dbo.findUnique
findUnique_2_4
0.1111111
8
Col02, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_4
0.1111111
12
Col01, Col02, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_2_3_4
0.1111111
12
Col02, Col03, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3_4
0.1111111
17
Col01, Col02, Col03, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3_4
0.1428571
13
Col01, Col02, Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3
0.1428571
13
Col01, Col02, Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_3_4
0.1428571
13
Col01, Col03, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_4
0.1666667
8
Col01, Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3
0.1666667
8
Col01, Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3_4
0.1666667
8
Col01, Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_3_4
0.1666667
8
Col03, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2
0.1666667
8
Col01, Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_4
0.1666667
8
Col01, Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_4
0.2
4
Col04
9
9
1.0000000000000000

dbo.findUnique
findUnique_2_3_4
0.25
8
Col02, Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_2_3
0.25
8
Col02, Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_3
0.25
9
Col01, Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_3_4
0.25
9
Col01, Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_3_4
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3_4
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_3
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_2_4
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_4
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1_3
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_1
0.3333333
4
Col01
9
9
1.0000000000000000

dbo.findUnique
findUnique_2
0.5
4
Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_3
0.5
4
Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_3_4
0.5
4
Col03
9
9
1.0000000000000000

dbo.findUnique
findUnique_2_4
0.5
4
Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_2_3
0.5
4
Col02
9
9
1.0000000000000000

dbo.findUnique
findUnique_2_3_4
0.5
4
Col02
9
9
1.0000000000000000


DROP TABLE dbo.findUnique

table_name	StatName	AllDensity	AvgLength	Columns	rows_sampled	rows	sample_pct
dbo.findUnique	findUnique_2_4	0.1111111	8	Col02, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_4	0.1111111	12	Col01, Col02, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_2_3_4	0.1111111	12	Col02, Col03, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3_4	0.1111111	17	Col01, Col02, Col03, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3_4	0.1428571	13	Col01, Col02, Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3	0.1428571	13	Col01, Col02, Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_3_4	0.1428571	13	Col01, Col03, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_4	0.1666667	8	Col01, Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3	0.1666667	8	Col01, Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3_4	0.1666667	8	Col01, Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_3_4	0.1666667	8	Col03, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2	0.1666667	8	Col01, Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_4	0.1666667	8	Col01, Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_4	0.2	4	Col04	9	9	1.0000000000000000
dbo.findUnique	findUnique_2_3_4	0.25	8	Col02, Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_2_3	0.25	8	Col02, Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_3	0.25	9	Col01, Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_3_4	0.25	9	Col01, Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_3_4	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3_4	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_3	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_2_4	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_4	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1_3	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_1	0.3333333	4	Col01	9	9	1.0000000000000000
dbo.findUnique	findUnique_2	0.5	4	Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_3	0.5	4	Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_3_4	0.5	4	Col03	9	9	1.0000000000000000
dbo.findUnique	findUnique_2_4	0.5	4	Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_2_3	0.5	4	Col02	9	9	1.0000000000000000
dbo.findUnique	findUnique_2_3_4	0.5	4	Col02	9	9	1.0000000000000000